This invention relates to a curable resin composition comprising a mixture and/or a preliminary reaction product of (a) a polyfunctional cyanate ester, prepolymer of the cyanate ester or coprepolymer of the cyanate ester and an amine (sometimes hereinunder referred to as component (a)), and (b) at least one compound selected from the group consisting of acrylic epoxy esters, methacrylic epoxy esters, prepolymers of acrylic epoxy esters, prepolymers of methacrylic epoxy esters, coprepolymers of acrylic epoxy esters and methacrylic epoxy esters and mixtures thereof (sometimes hereinunder referred to as component (b)) and also relates to a curable resin composition comprising a mixture and/or a preliminary reaction product of (a) a polyfunctional cyanate ester, prepolymer of the cyanate ester or coprepolymer of the cyanate ester and an amine, (b) at least one compound selected from the group consisting of acrylic epoxy esters, methacrylic epoxy esters, prepolymers of acrylic epoxy esters, prepolymers of methacrylic epoxy esters, coprepolymers of acrylic epoxy esters and methacrylic epoxy esters and mixtures thereof, and (c) a polyfunctional maleimide, prepolymer of the maleimide or coprepolymer of the maleimide and an amine (sometimes hereinunder referred to as component (c)). Cured resin obtained by curing each of the resin compositions has excellent impact-resistance, adhesive power, heat-resistance and chemical resistance.
In the prior art, the cured resin obtained by cast-molding a composition containing a polyfunctional maleimide and a polyfunctional cyanate ester has low impact resistance. Similarly, the cured resin obtained by cast-molding cyclopentadiene resin is fragile.